Where did West Nile virus come from?
West Nile virus was first identified in the West Nile district of Uganda in 1937, and has since been found in other parts of Africa, Eastern Europe, West Asia, the Middle East, and the United States. The strain of virus found in the United States most closely resembles that found in the Mediterranean and Middle East. The virus has been reported in nearly all states. Q: How is West Nile virus transmitted? A: Mosquitoes draw the virus from infected birds and transmit it to other animals, including humans, through bites. West Nile viral encephalitis develops when the virus multiplies and crosses the blood-brain barrier. West Nile virus is not transmitted directly from animal to person, person to animal, animal to animal or person to person; however, rare instances of transmission via organ transplantation, blood transfusion, transplacental infection, and breastfeeding have been reported. Cats have been infected experimentally by eating WNV-infected mice. Ticks infected with the virus have